1. Field of the Invention
This invention relates to counters and storage arrangements for maintaining records of usage of consumables in equipment, particularly office equipment.
This invention provides an office machine that does not increase the cost of disposable consumables, that does not require an operator to record the number of uses, and that enables the number of uses or the life of a number of consumables to be controlled.
In addition, according to this invention, because the storage area within the office machine has flexibility, it has the effect of minimally increasing the cost of the office machine itself.
2. Description of Related Art
In the prior art, printers or copying machines utilizing the electrophotostatic copying technique rapidly gained popularity because of features like high speed, high quality, and low noise in operation. It is necessary, however, to replace their consumables such as photosensitive drums and brushes at the end of a predetermined life. The proper determination of the replacement timing and proper maintenance of the consumables leads to good printing quality and extended life of the product. Particularly, these consumables have recently been modularized and can be replaced by the user himself so that the demand for easy determination of the time for exchange is increasing.
Conventionally, a counter dedicated to specific consumables is mounted in the office machine and is reset to start counting from an initial value whenever the related consumables are replaced. Therefore, in a case where a plurality of consumables are alternatively used for applications, the intervention of an operator is required to record the contents of the counters whenever the corresponding consumables are exchanged. The manual intervention, however, leads to a low reliability with respect to the contents of the counters.
On the other hand, there are arrangements in which a counter or count storage area is provided on each of the consumables to be counted. For example, Japanese Published Examined Patent Application No. 61-9149, published on Mar. 20, 1986, discloses a typewriter in which a counter is provided in the typewriter and a magnetic tape is provided in a cartridge case, which contains a type wheel as a consumable, for storing the number of uses of the wheel. In addition, Japanese Published Unexamined Patent Application No. 60-63551 published on Apr. 11, 1985, discloses a counter in a kit containing all or parts of consumables such as a photosensitive drum, a developer, a cleaner, and a charging unit instead of providing a counter on the image forming device body.
Providing a counter or count storage area for each consumable is undesirable because it leads to increased cost of the consumables. In addition, the count stored in the consumables is easily lost and tends to be unreliable in providing data for determining whether the consumables are within the life guaranteed by the manufacturer. This may be solved by providing a number of dedicated counters or count storage areas in the office machine. If there are a plurality of consumables with the same functions which are alternately used, it is difficult to determine how many counters or count storage areas should be provided, and the method is expensive with little possibility of attainment.
Therefore, one object of the invention is to provide an improved office machine for which the number of uses or the life of each disposable replacement part or consumable can be managed without increase of cost or intervention by the operator.
Another object of the invention is to provide an office machine with a new arrangement that minimizes the cost increase of the office machine by providing flexibility for counting of the life of each kind of consumables and storing of the count.